2-Stroke suddenly won't start, was excellent unti now

[tinnews]

I've been using my Ryobi strimmer all morning on and off, no problems re-starting hot or cold. I stopped and started it several times.

Around lunch time it ran out of fuel so I refilled it and since then I haven't been able to get a peep out of it, it's not even fired once. I've checked that there's a spark (several times!) and it smells as if fuel is getting through. It has fresh fuel and a new plug. I have also left it for a longish period and retried the cold start sequence, still no joy.

What can I be doing wrong?

[The Natural Philosopher]

is it even coughing?

If its anywhere like getting fuel and a spark it should at least fire a bit.

If its doing nothing there are three things that are indicated

- no spark at all (is the on-switch ON?' Done that too many times).

- no fuel at all - but the bulb pump prime should take care of that.

- far too much fuel and the plug is flooded. Remove and dry, then replace.

[tinnews]

Very rarely, most of the time it does just nothing.

That's my feeling too, but it's not helping me much! :-)

I keep thinking this and checking for a spark, whenever I check for a spark it's there OK, though not incredibly strong.

There's always fuel in the bulb.

Possibly, but whenever I check for spark etc., the plug isn't wet.

[Andy Dingley]

Check the cylinder is still attached to the crankcase. Any black oily leakage around the joint? Common fault. Five minutes and a #27 Torx bit (a slightly obscure size) fixes it.

[Jo Stein]

Also turn the motor a little with the plug out, in order to make the motor more dry. It also helps to write on the plug with an ordinary carbon pencil. I do not know why that helps. The little carbon on the plug "pins" may help to start the "fire".

[Muddymike]

I've been using my Ryobi strimmer all morning on and off, no problems

Do you have a butane or propane torch? If so try directing some gas into the air filter when trying to start it. If it fires up then stops when you take the gas away you have fuel starvation. If it continues to run problem solved.

Mike

[Simon Cee]

If fuel is getting thru then the plug WILL be wet. Suspect a fuel blockage somewhere - which is probably why it stopped before, ie it didn't actually run out of fuel as you thought. Dismantle thr carb?

[Jules Richardson]

Hmm, try disconnecting the spark and then turning it over a few times before checking the cylinder for fuel - "smells as if fuel is getting through" might not necessarily be a good test, but the interior of the cylinder should be obviously wet with fuel if the carb's doing its job and there's nothing to ignite the mixture.

In addition to other comments, I suppose it might be a sheared flywheel key, and the flywheel has spun on the crank such that the timing's completely out; that could account for presence of spark and fuel mix, but no actual running. It seems unlikely if it stopped due to lack of fuel (rather than sudden impact with an obstacle), but not impossible.

cheers

Jules

[John Rumm]

Try what everyone else said, however one thing worth also checking is the cylinder bore. When this happened to my first ryobi, it turns out it had ingested a bit of its own carb or some other metallic foreign body. The results were not pretty:

on Ryobi 2!)

[Tim+]

A problem we had with an outboard once was caused by the shearing of the woodruff key holding the flywheel in the right position on the crank resulting in sparks at the wrong time. Potentially something similar?

Tim

[tinnews]

I've dismantled it a couple of times now, nothing obvious amiss though how to tell whether the main jet is blocked or not I don't quite know. It is all very small and difficult to see what's what.

[tinnews]

At my last attempt to see what was wrong I took it almost completely apart and put it back together again including removal of top of cylinder etc. Nothing really appears to be wrong.

I'm wondering if I'm suffering from 'tunnel vision' because it stopped working just when it ran out of fuel. It did make a couple of odd rattles in the last few minutes before it stopped and I'm wondering if something vital has broken inside (the only place I haven't looked inside is the crankcase/exhaust).

[tinnews]

I'm not sure I've got enough hands to to that! :-)

Maybe an exercise to try with a helper when I get back from a short holiday we're about to take.

[tinnews]

Yes, I'm wondering about that, I've not seen it wet with fuel at all since it died. Maybe I *have* got a blocked jet.

I'm pretty sure it didn't suffer a sudden stop, though it is possible as I was running with a brush cutter blade on it when it stopped.

[tinnews]

Yes, someone else has suggested this too. I will investigate.

Thanks everyone for all the helpful ideas and comments. I don't think I have time today/tomorrow to waste any more time on it but I will have a good, thorough look at it when I come back in ten days or so.

[The Natural Philosopher]

IF it started misfiring and then cut it improves the chance that the key has sheared throwing the timing out.

[The Natural Philosopher]

It certainly is possible that it sheared partially under heavy load and then finished the job off under acceleration later on.

The key is the last defence against a broken or bent crankshaft.

If you can get the flywheel off its a simple fix. The key(sic!) is getting the flywheel off.

[Muddymike]

I do it by kneeling on the workshop floor with the machine on the floor and the torch lying next to it with nozzle pointing up into the bottom of the air filter. It doesn't have to be perfectly aligned, as long as the air sucked in has an adequate mix of propane. I mostly start mine from cold like this now as it's a bugger otherwise.

Mike

[RobertL]

starting hot or cold. I stopped and started it several times. Around lunch = time it ran out of fuel so I refilled it and since then I haven't been able= to get a peep out of it, it's not even fired once. I've checked that there= 's a spark (several times!)=20

Just becuase you ge ta sprak when the plug is out id not a guarantee. If t= he spark is weak for some reason it is possible to get a spark in air (with= the plug out) but not when it is inside the cylinder.

Robert

[Gib Bogle]

When my mower refuses to start I leave it for an hour or so. I never went so far as to take a short holiday, but I can see how it could get to that.